.travis.yml

language: node_js
node_js:
  - '8'

install:
  - npm install -g markdownlint-cli
  - npm install -g markdown-spellcheck
  - npm install -g markdown-link-validator

script:
  - |
    CHANGED_MD_FILES=""
    if [ -z "${TRAVIS_COMMIT_RANGE}" ] ; then
      CHANGED_MD_FILES="$(git diff --name-only ${TRAVIS_COMMIT} -- | grep "^.*\.md$")"
    else
      COMMIT1="$(echo ${TRAVIS_COMMIT_RANGE} | cut -f 1 -d '.')"
      COMMIT2="$(echo ${TRAVIS_COMMIT_RANGE} | cut -f 4 -d '.')"
      CHANGED_MD_FILES="$(git diff --name-only ${COMMIT1}..${COMMIT2} -- | grep "^.*\.md$")"
    fi
    test -z "${CHANGED_MD_FILES}" && exit 0
    markdownlint ${CHANGED_MD_FILES} || exit 1
    mkdir tmp-md-changed-files
    cp -rf ${CHANGED_MD_FILES} tmp-md-changed-files
    markdown-link-validator tmp-md-changed-files || exit 1
    mdspell -a -n -r -x --en-us ${CHANGED_MD_FILES} || exit 1